From ba2aa30ec96ff7850a06166767344ca9fc6b0b84 Mon Sep 17 00:00:00 2001
From: Stephan Hilb <stephan@ecshi.net>
Date: Fri, 26 May 2023 23:44:37 +0200
Subject: [PATCH] Enum: fix stackoverflow in `hash` for custom enum subtypes
 introduced in #49777 (#49964)

---
 base/Enums.jl | 2 +-
 test/enums.jl | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/base/Enums.jl b/base/Enums.jl
index 2c18dbca72fcd..45a1b66753484 100644
--- a/base/Enums.jl
+++ b/base/Enums.jl
@@ -27,7 +27,7 @@ Base.read(io::IO, ::Type{T}) where {T<:Enum} = T(read(io, basetype(T)))
 Compute hash for an enum value `x`. This internal method will be specialized
 for every enum type created through [`@enum`](@ref).
 """
-_enum_hash(x::Enum, h::UInt) = hash(x, h)
+_enum_hash(x::Enum, h::UInt) = invoke(hash, Tuple{Any, UInt}, x, h)
 Base.hash(x::Enum, h::UInt) = _enum_hash(x, h)
 Base.isless(x::T, y::T) where {T<:Enum} = isless(basetype(T)(x), basetype(T)(y))
 
diff --git a/test/enums.jl b/test/enums.jl
index 757aa26a061be..6eb9360e08a23 100644
--- a/test/enums.jl
+++ b/test/enums.jl
@@ -184,6 +184,10 @@ end
 @enum HashEnum3 Enum3_a=1
 @test which(hash, (HashEnum3, UInt)).sig != Tuple{typeof(hash), HashEnum3, UInt64}
 
+# Check that generic `hash` on custom enum subtypes works.
+struct HashEnum4 <: Enum{Int} end
+@test hash(HashEnum4(), zero(UInt)) == invoke(hash, Tuple{Any, UInt}, HashEnum4(), zero(UInt))
+
 @test (Vector{Fruit}(undef, 3) .= apple) == [apple, apple, apple]
 
 # long, discongruous